The Lotus F1 team is facing legal action over its attempt to use the Team Lotus name from next year.
Proton, which owns Lotus road cars, has challenged Lotus Racing team boss Tony Fernandes’s right to use the name.
Nadzmi Salleh, Proton chairman, said: “Tony Fernandes has no rights to use the Lotus brand in the 2011 season.
“We will strongly resist any attempts by him to use our brand without our permission and will withdraw our sponsorship of the Lotus Racing team.”
He added: “We are the owners of this brand, and will take all necessary steps to protect it.”
A press release from Proton stated: “Proton will support Group Lotus in taking all necessary steps to protect its rights in the ‘Lotus’ name, including resisting any attempts by Mr. Fernandes or his companies, or any other unauthorised person, to use the ‘Lotus’ name in the 2011 Formula 1 season.”